Water Pump

ABSTRACT

A water pump has a pump housing having a water inlet and a water outlet. A driven pump impeller is arranged in the pump housing. The pump impeller is a diagonal impeller with a carrier plate having a conical shape. The water inlet and the water outlet are arranged such that a water intake direction and a water exit direction are substantially perpendicular to one another.

The invention concerns a water pump, in particular for use in garden ponds and in the field of aquaristics, according to the preamble of claim 1.

In practice, pumps are common in this field that have a motor-driven radial impeller so that the water to be pumped is deflected by a deflection angle of 90 degrees. In this way, these pumps fulfill the existing requirements with regard to the particular configurations according to which a deflection by approximately 90 degrees must generally occur. Even though such water pumps generate a relatively high delivery pressure, they have a relatively small delivery rate. If it is desired to achieve with such a pump a great delivery rate, the required power input is very high.

It is therefore an object of the present invention to provide a water pump with improved efficiency with regard to the delivery rate. This object is solved according to the invention by a water pump having the features of claim 1.

By using a pump impeller that is embodied as a diagonal impeller with a substantially conical carrier plate, the flow is guided diagonally through the impeller and is deflected by a smaller angle in comparison to a radial impeller. When conveying large quantities of water, the deflection losses remain small and the efficiency is improved. Pumps designed in this way have the advantage that at reduced pressure more water volume can be conveyed. Preferably, such pumps are therefore used in filter devices where little pressure but a high flow rate are required. By means of the improved efficiency, the pump according to the invention requires significantly less power input than the known pumps with a radial impeller. Also, the pump according to the invention with its great flow rate efficiency can be built more compact than pumps with conventional impellers. In order to obtain the same flow rate, the diameter of a conventional impeller would have to be greater by a factor 1.5. The compact configuration of the pump according to the invention enables also an especially cost-efficient manufacture because only relatively small tools, in particular, injection molds for plastics, are required.

Further advantages and details result from the dependent claims and an embodiment illustrated in the drawings that will be explained in the following; it is shown in:

FIG. 1 a water pump according to the invention in longitudinal section; and

FIG. 2 the pump impeller of the pump of FIG. 1 in a perspective exploded view.

The illustrated water pump has a pump housing 1 and a motor housing 2 connected thereto in a seal-tight way; together they form the complete housing of the pump. The pump housing 1 has a water inlet 3 and a water outlet 4 which are preferably centrally arranged on the top side of the pump housing. In the interior of the pump housing 1 between the water inlet 3 and water outlet 4 the pump impeller 5 configured as a diagonal impeller is arranged. The latter is shown in FIG. 2 in a perspective view.

The pump impeller 5 has according to the present invention a substantially conical carrier plate 6 by which the water flow, indicated by the arrows 7, is guided diagonally through the pump housing. In cooperation with the arrangement and shape of the water inlet 3 and the water outlet 4, preferably arranged essentially perpendicular to one another, the water flow 7 exits the pump in a direction deflected by approximately 90 degrees relative to the intake direction of the water flow 7. The carrier plate 6 of the pump impeller 5 defines a cone angle α of preferably 80 degrees to 100 degrees. In this way, an optimal flow deflection is achieved and the flow losses are minimized.

The illustrated embodiment is especially advantageous because the outer blade edges 8 of the impeller blades 9 extend in the diagonal direction, parallel to the direction of the water flow 7, and to the surface of the carrier plate 6. In this way, the impeller blades 9 can be matched to the contour of the stationary pump housing 1 so that they form a seal gap 10 thereat. In this special configuration, it is possible to provide with standard tolerances of the components a tight seal gap 10 between the stationary pump housing 1 and the rotating impeller 5. This leads to a minimal inner leakage flow and thus to an improved hydraulic efficiency. The pump can be designed especially compact when the seal gap 10 is arranged in the transition area between the water inlet 3 and the water outlet 4.

The pump of the illustrated embodiment is optimized with regard to its flow behavior and its smooth running in that the impeller blades 9 have an airfoil profile and the carrier plate 6 of the pump impeller 5 has a pointed rear edge 13. An excellent flow distribution when the flow is directed against the pump impeller 5 is achieved moreover in that the leading edges 14 of the impeller blades 9 facing the flow are oriented substantially perpendicularly to the flow direction of the water in the water inlet 3.

Centrally within the cone tip of the carrier plate 6 of the pump impeller 5 there is preferably a penetration 15 or a bore serving for cooling and venting purposes.

The pump impeller 5 can be produced particularly cost-efficient as an injection-molded plastic part. In order to optimize wear and gliding properties, preferably a metal ring is embedded by injection molding and serves as a bearing receptacle. The metal ring 16 is shown behind the shaft 17 in the exploded view of FIG. 2; however, in the assembled component it is arranged within the shaft 17. By means of the metal ring 16, the pump impeller 5 is supported on an electric motor 18 and is driven by the motor in rotation.

The water pump according to the invention is excellently suitable because of its compact configuration, its high conveying output and its minimal power input as a circulating pump primarily for applications in which a permanent operation is required. In comparison to conventional pumps, significant energy savings are achieved. 

1-12. (canceled)
 13. Water pump comprising: a pump housing having a water inlet and a water outlet; a driven pump impeller arranged in the pump housing; wherein the pump impeller is a diagonal impeller with a carrier plate having a conical shape.
 14. Water pump according to claim 13, wherein the water inlet and the water outlet are arranged such that a water intake direction and a water exit direction are substantially perpendicular to one another.
 15. Water pump according to claim 14, wherein the pump impeller has impeller blades having outer blade edges, wherein the outer blade edges of the impeller blades extend in a diagonal direction relative to the water intake direction and the water exit direction.
 16. Water pump according to claim 15, wherein the outer blade edges of the impeller blades extend parallel to the water flow.
 17. Water pump according to claim 15, wherein the outer blade edges of the impeller blades define a seal gap together with an inner contour of the pump housing.
 18. Water pump according to claim 17, wherein the seal gap is arranged in a transition area between the water inlet and the water outlet.
 19. Water pump according to claim 15, wherein the impeller blades have an airfoil profile.
 20. Water pump according to claim 13, wherein the carrier plate of the pump impeller has a pointed rear edge.
 21. Water pump according to claim 13, wherein the carrier plate of the pump impeller has a cone tip provided with a penetration.
 22. Water pump according to claim 21, wherein the carrier plate of the pump impeller has a cone angle of 80 degrees to 100 degrees.
 23. Water pump according to claim 13, wherein the pump impeller is an injection-molded plastic part and has at least one embedded ring of a different material.
 24. Water pump according to claim 23, wherein the embedded ring is a metal ring.
 25. Water pump according to claim 13, wherein the water outlet is arranged essentially centrally on a top side of the pump housing. 